The present invention relates, in general, to electronics, and more particularly, to methods of forming semiconductor devices and structure.
In the past, the semiconductor industry utilized various methods and structures to form operational amplifiers. One design of previous operational amplifiers generally provided an operational amplifier with a voltage swing on the output that went substantially from one power supply rail to the other. Additionally, the output desirably supplied a relatively large current to load the connected to the output of the operational amplifier. However, under no load conditions such operational amplifiers generally had a large quiescent current. Some of these previous operational amplifiers also required complex circuitry and often included several sets of differential pair connected transistors in order to implement the operational amplifier.
Accordingly, it is desirable to have an operational amplifier that has a large output voltage swing, that can supply large currents to a load, and that has a small quiescent current under no load conditions.
For simplicity and clarity of the illustration, elements in the figures are not necessarily to scale, and the same reference numbers in different figures denote the same elements. Additionally, descriptions and details of well-known steps and elements are omitted for simplicity of the description. As used herein current carrying electrode means an element of a device that carries current through the device such as a source or a drain of an MOS transistor or an emitter or a collector of a bipolar transistor or a cathode or anode of a diode, and a control electrode means an element of the device that controls current through the device such as a gate of an MOS transistor or a base of a bipolar transistor. Although the devices are explained herein as certain N-channel or P-Channel devices, a person of ordinary skill in the art will appreciate that complementary devices are also possible in accordance with the present invention. It will be appreciated by those skilled in the art that the words during, while, and when as used herein are not exact terms that mean an action takes place instantly upon an initiating action but that there may be some small but reasonable delay, such as a propagation delay, between the reaction that is initiated by the initial action.